Heretic music

The Heretic soundtrack was created by Kevin Schilder of Raven Software. As should be expected from the fantasy setting of the game, in contrast to Doom's science fiction theme, the music is composed in a completely different style. Heretic's soundtrack is more ambient and has diverse instrumentation, with significant use of percussion, harps, and choral voices. Many tracks are highly rhythmic and evoke an exotic, fantasy action atmosphere similar to typical motion picture soundtracks in the same genre. The Heretic soundtrack was meant to sound "dark, angry, and dissonant", making use of the, diminished chords, and whatever other musical methods "sounded right" to evoke this mood.

The tracks in Heretic are only labeled in the IWAD with the headers of the levels for which they were originally written. Track names, and a few comments, were provided by Schilder after being queried about it, the relevant documents are available here.

Original MIDI files
On July 25, 2023, user The Almighty Egg shared the original MIDI files provided to them by Kevin Schilder in a thread on Doomworld forums. These files have their original timestamps. Some tracks have multiple versions showing their changes during the composing process. Some filenames have an "F" suffix to indicate that this is the final version that is used in the game.